Spark plug



oct. s, 1925. 1.556,251

H. SAMPSON SPARK PLUG Filed Feb. 1, 1924 ATTORNEYS Patented Oct. 6, 1925.

UNITED STATES HARRY sAMPsoN, oF LONG BEACH, NEW YORK.

SPARK PLUG.

Application led February To all whom t may concern.'

Be it known that I, Haren' SAMrsoN, a citizen of the United States, and a resident of Long Beach, in the county of Nassau and State of New York, have invented a new and Improved Spark Plug, of which the following is a full, clear, and exact description.

This invention has relation to an ignition or spark plug used in connection with internal combustion engines and aims for its principal object to provide a spark plug in which the porcelain or insulating element of the plug carries both electrodes and is detachably associated with the shell or body of the plug whereby upon removal of the porcelain or insulator member both of the electrodes carried thereby may be readily cleaned to free the same of carbon deposits.

By constructingr a spark plug in this man ner it is obvious that one of the principal advantages derived therefrom resides in the elimination of the necessity of ren'loving the threaded shell or body of the plug from the threaded bore in the cylinder into which it tits, thereby eliminating possible mutilation of the threads and leakage at this point resulting in loss of compression.

The invention furthermore contemplates a spark plug provided with a removable or detachable porcelain or other insulator core by which the central and grounded electrodes are carried and in which the body or shell is equipped with a resilient conductor element engageable with the grounded electrode when the core is in place, whereby the grounded electrode is grounded on the shell and cylinder.

The invention comprehends as a still further object in a plug of the character set forth a means for detachably associating the ground electrode with the core whereby the same may be readily disassembled when the core is removed from the shell to facilitate the cleaning of the point of the electrode.

As a further object the invention comprehends in a spark plug structure of the character set forth a means for retaining and sealing the porcelain or insulator core in assembled relation to positively preclude accidental displacement and leakage between the elements of the plugs.

As a Still further object the invention resides in the provision of a spark plug ot the character set forth which is comparatively simple in its construction, inexpensive to manufacture and produce, and which is 1, 1924. Serial No. 689,954.

thoroughly reliable and highly etlicient in its purpose.

. `lilith the above recited and otherI objects .in view, the invention resides in the novel construction set forth in the following Specilicatu'in, particularly pointed out in the ap pendcil claim and illustrated in the accompartying drawings, it being' understood that the right is reserved to embodiments other than those actually illustrated herein to the vt'nll extent indicated by the general meaning of the terms in which thelclaiins are ext pressed.

.ln the drawings- Figure 'l is a vertical sectional view through a spark plug' constructed in accordance with the invention.

Fig. 2 .is a cross sectional View there through taken approximately on the line ndie ted at 2 2 in Fig. 1.

Y 3 is a perspective view of the ground "ode removed from the porcelain or core.

H `leferring to the drawings by characters ot refer-ence` 1() designates the cylindrical body or shell of the plug which is formed with a reduced exteriorly threaded lower end 11 adapted for threaded engagement in the spark plug opening of the cylinder C of an internal combustion engine. The body or shell 10 is formed with an upper enlarged bore 1,2 while the reduced lower threaded end is provided with a communicating reduced bore 13, the bores 12 and 13 being provided with an annular truste-conical shoulder or seat l-l at their juncture. The upper end of 'the bore 12 is provided with an outwardly flared or conical seat 1:3. The bore 1? is further provided with a longitudinal groove 1G extending from the seat or shoulder 1.4i to its lower end. The porcelain or insulator core 17 is provided with an upper portion 1S, an intermediate portion 1.9 and a lower portion 20, the former being of a greater diameter than the intermediate portion and the latter being of an appreciably lesser diameter than the interni@ diate portion.

External annular frusto-conical shoulders 2l and 22 are formed at the juncture of the portions 18 and 19 and 19 and 2O which are respectively designed to coaet with the seats or shoulders 15 and lll to clamp therebetween sealing gaskets 23 and 24. The porcelain or insulator core 17 is further provided with a central or axial bore 25 extending through the. portions 18, 19 and 2O and a central conductor stem 26 extends through the bore and is provided with threaded upper and lower ends 27 and 28. The upper end has arranged thereover the washers 29 and 30 and engage therewith a binding nut 31, while the lower end has arranged thereover a washer 32 and engage therewith a retaining nut 33. The lower projecting threaded terminal 28 of the stem 26 serves as the insulated or central electrode of the plug. The ground electrode 34 consists of an arm 35 provided at its upper end with a sleeve 36 and at its lower end with an inwardly projecting terminal 37. The sleeve y 36 is of a diameter to snugly tit the lower projecting portion 20 of the core 17 and is provided with a bayonet slot 38 communieating with its upper edge and designed to coact with a radially projecting lug or teat 39 adjacent the juncture of the portion 2O with the portion 19. This construction admits of and facilitates the association of the ground electrode with the porcelain or insulator core 17 and when so associated therewith the terminal 37 underlies and is spaced from the threaded terminal 28 constituting the central or insulated electrode to produce the spark gap G. In order to establish electrical communication between the shell or body l() and the ground electrode 34, a leaf spring 40 of a conducting material is secured to the shell or body 10 within the groove 16 of the reduced externally threaded lower portion 11 and projects radially inward under its normal inherent resiliency a suilicient distance to engage and contactv with the arm 35. In order to retain the porcelain or insulator core 17 in the shell or body 10 with the sealing gaskets 23 and 24 in proper sealin relation to the coacting seats 2l and 15 an 22 and 14, a plurality of clips 41 are employed which are provided with hooked upper terminals 42 engageable in the notches 43 in the up r end of the porcelain or insulator core 1 At the lower ends the clips 41 are provided with hooked terminals 44 engageable with the radially projecting keeper lugs 45 on the body or shell 10.

lnuse of the plug, after the body 10 has been initially threaded into the plug openrelease the clips 41 from the keepers 45. The 65 porcelain or insulator core 17 may then be removed leaving the shell or body 10 in place. After the core or porcelain 17 is removed the ground electrode 34 may be detached. It is also obvious that regulation of the spark gap may be ei'ected at any time by adjusting the nuts 31 and 33 to cause the projection or retraction of the lower threaded end 28 from the lower end of the forcelain or core. porcelain and component cleansed and reassembled t e same is rein-V serted in the shell or body 10 so that the ground electrode 34 coacts and engages with the spring engaged with the keepers 45 and the plug is then ready for use.

I claim:

A spark plug comprising a shell or bod member adapted for threading into a. oy 1l inder, a removable insulator core mounted e therein, insulated and grounded electr carried by said core, a resilient conducter element carried by the shell on body member and engageable with the when the core is seated shell and core each having a plurality of coacting gasket seats, gaskets interposed between said seats and means eng cable with the shell and core for holding t e same in assembled relation, for clamping the gaskets @s in sealed relation to the seats and for posi tioning and retaining, the groundedelectrode in contact with the resilient conductor element, said means eomprisinga lural j of 9o @Per 8.5 n".

and

clips having hooked terminals, projecting radially from the shell notched portions in the core with which lr and notches the hooked terminals ofy lig:

clips engage.

HARRY SAMPSON. f

After the removed core or G5 parts have been ,M

conductor 40, the clips being rel0 ground electrode s0 in the shell, said 5; 

